ScienceShot

Backpacking on Mars

At the height of the summer travel season, the U.S. Geological Survey (USGS) has released its most detailed geological map of Mars. Unlike images that depict the Red Planet’s surface in terms of elevation alone (bright colors from white through red to blue), the new map (muted colors) breaks the planet into nearly 50 types of regions based on their elevation, age, types of rocks, and other factors. Most of the data used to compile the new chart came from four spacecraft that have orbited the Red Planet during the past 16 years—Mars Global Surveyor, Mars Odyssey, Mars Express, and Mars Reconnaissance Orbiter—but a small bit of info used to “ground-truth” the map came from rovers. Among other news, Mars’s surface is generally older than previously thought, USGS reports. Besides serving as eye candy for Mars enthusiasts, the detailed map will help mission planners select future landing sites where they can most efficiently explore the Red Planet’s geological record.